Paleobiology Commons^™

Looking For The Oldest Diatoms, Karolina Brylka, Sylvain Richoz, Andrew J. Alverson, David J. Conley

Biological Sciences Faculty Publications and Presentations

Paleontological observations of ancient flora and fauna provide powerful insights into past diversity and relationship dynamics between organisms and their environments. Diatoms are globally distributed protists that influence major biogeochemical cycles and sustain oceanic food webs. The fossil diatom record extends 120 million years back to the Early Cretaceous where rare deposits were discovered worldwide and are occasionally represented by diverse communities. However scarce, the taxonomic richness and geographical spread of these diatom communities suggest prior evolutionary events and therefore earlier deposits. To complement the existing fossil information and to discover diatom deposits predating 120 Ma, we examined 33 study …

Rodent Dental Microwear Texture Analysis As A Proxy For Fine-Scale Paleoenvironment Reconstruction, Jenny H. E. Burgman

Graduate Theses and Dissertations

Dental microwear texture analysis (DMTA) of fossil fauna has become a valuable tool for dietary inference and paleoenvironment reconstruction. Most of this work has utilized larger taxa with larger home ranges. These studies may result in broader-scale habitat inferences that could mask the details of complex mosaic habitats. Rodent DMTA offers an opportunity to work at finer spatial scales because most species have smaller home ranges. Rodents are also keystone species within their ecosystems, abundant, ubiquitous, and found in many fossil deposits. These attributes make them excellent proxies for environmental reconstructions. However, the application of DMTA to rodents remains relatively …

Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura

Graduate Theses and Dissertations

The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed.

Despite the difference in facies and sedimentary architecture, the isotope composition does not change …

Paleoclimate Implications From Stable Isotope Analysis Of Sedimentary Organic Carbon And Vertebrate Fossils From The Cedar Mountain Formation, Ut, U.S.A., Garrett Andrew Hatzell

Graduate Theses and Dissertations

Oxygen and carbon isotopic compositions of fossilized vertebrate teeth and bone were analyzed to determine isotopic values of vertebrate faunal diet from the early Cretaceous Cedar Mountain Formation of Utah. Results for δ18O of PO4 (δ18Op) (Suarez et al., 2014) from the same data set have been compared to the δ18O of CO3 (δ18Oc) portion of teeth and turtle shell to determine if diagenetic alteration of the isotopes has occurred by plotting the line of best fit equation that models the relationship between unaltered δ18OP and δ18OC of modern mammals from Iacumin et al., 1996. Results indicate slight diagenesis of …

Tempo And Mode Of Domestication During The Neolithic Revolution: Evidence From Dental Mesowear And Microwear Of Sheep, Melissa Zolnierz

Graduate Theses and Dissertations

The Neolithic Revolution marked a dramatic change in human subsistence practices. In order to explain this change, we must understand the motive forces behind it. Researchers have proposed many different stimuli, with most theories invoking environmental dynamics, human population density increases beyond environmental carrying capacity, and the natural outgrowth of human and plant/animal interactions. However, unanswered questions remain concerning the mechanics of animal domestication. Traditional studies of changing faunal morphology and skeletal population profiles offer some clues, but such research has had limited success identifying stages intermediate between wild and domesticated forms, which makes it difficult to discern initial attempts …

Hypothetical Origins Of Paleozoic Fossils From The Gulf Coastal Plain Of Arkansas, Karen Arbuckle

Journal of the Arkansas Academy of Science

A fauna of reworked Paleozoic fossils has been found in chert pebbles from the Gulf Coastal Plain in eastern Columbia County, Arkansas, although the nearest mapped exposure of Mississippian and Pennsylvanian rocks are fifty-five miles northward in the southern edge of the Ouachita Mountains. The surficial rocks at the collection site have been referred to the Claiborne Group of Eocene age by the authors of the geological map of Arkansas. Additional outcrops containing similar Paleozoic fossils have been found within a 15-mile radius. The fauna includes both lacy and twig-like bryozoans, articulate brachiopods, tabulate and rugose corals, stalked echinoderms, gastropods, …

Taxonomic Note On Fossil Glyptostrobus In Northeastern Arkansas, Eugene B. Whittlake

Journal of the Arkansas Academy of Science

Two papers by Brown (1936, 1962) are reviewed and discussed in relation to the validity of specific names applied to the fossil Glyptostrobus as found in North American deposits. Evidence is presented supporting the contention that G. nordenskioldi Brown n. comb, is the valid name for Glyptostrobus specimens from the Hooker site of northeastern Arkansas.

Consideration Of Macro-Climatic And Macro-Biotic Change In The Ozark Highlands During Post-Glacial Times, Kenneth W. Cole

Journal of the Arkansas Academy of Science

Climatological, pedological and faunal investigations conducted in the Upper Midwest and the Ozark Highlands indicate that the environment to which man in the Ozarks was adapting over the past 12,000 years has undergone several major shifts, beginning with a cool-moist boreal forest situation followed by a period of warming and aridness resulting in prairie and deciduous forest climaxes and subsequently, in the last 4000-5000 years, change to the pattern reflected by present conditions.

Eddy Bluff Shelter Of Beaver Reservoir Of Northwest Arkansas, James D. Morrison

Journal of the Arkansas Academy of Science

No abstract provided.